Suppose that we record a spectrum with the simple pulse-acquire sequence using a 90° pulse applied along the x-axis. The resulting FID is Fourier transformed and the spectrum is phased to give an absorption mode lineshape.
We then change the phase of the pulse from x to y, acquire an FID in the same way and phase the spectrum using the same phase correction as above. What lineshape would you expect to see in the spectrum? Give the reasons for your answer.
How would the spectrum be affected by: (a) applying the pulse about -.v; (b) changing the pulse flip angle to 270° about x?